For a while now, my AmazonBasics PETG filament has been working like a charm. Now, it is balling up on my nozzle. I've tried slowing it down, re-leveling the bed, etc. I don't want to go through the hassle of replacing my nozzle with a Micro-Swiss all metal 0.4 mm nozzle. I've tried the other extruder which I know works with PLA, but same results. I'm using a Flashforge Creator Pro(2016).
It could be that you're having issues now due to the filament absorbing moisture. I had a big problem with it doing that when I had waited for a few months after opening my filament. Dehydrated it using just my heated plate and a foil lined box over the top and it fixed it right up. If that's something you haven't tried yet perhaps that is what is causing you some grief.
PETG does this. PETG is like glue when soft this is why when you level the bed you have to add an additional 0.1 mm distance for PETG. PETG should not be as close as PLA, but futher away. It will stick to the hotend so preferably change the hotend from brass to a nickle plated nozzle (e.g. Micro Swiss, PETG does not stick to that nozzle at all).